Flexible hinge ring



Dec. 20, 1932. 5 w MCKELLIP 1,891,566

FLEXIBLE HINGE RING Filed Jan. 7, 1932 Patented Dec. 20, 1932 -1mmiswis PATENT OF SPENCER w. McK LLIP, or PHILADELPHIA, PENNSYLVANIA, AssIGNoE 'ro PHIL.

DELPHIA STORAGE BATTERY ooMPANY, or PHILADELPHIA, PENNSYLVANIA, A con 7 PORATION 0P PENNSYLVANIA FLEXIBLE HINGE RING Application filed January 7, 1932. Serial No. 585,372.

This invention relates to, supporting hinge rings for sound reproducing dia-v phragms, such, forexample, as the diaphragms of sound reproducers of radio receivers. The general object of the invent on is to provide a novel supporting ring having the desirable characteristics set forth fully hereinafter and which is especially adapted for supporting the conical diaphragm of the electrodynamic. reproducer of a modern radio receiver. I

A more specific object of the invent on 1s to provide an inexpensive mounting or supporting ring for resiliently attaching a conical diaphragm to the diaphragm housing.

Another object of the invention is to provide a diaphragm supporting ring which I readily enables a change in the frequency response characteristics of the diaphragm vwithout changing the other elements of the reproducer. As pointed out hereinafter, the naturalor resonant frequency of the reproducer may be varied by simply varying the construction of the supporting ring as to its constituent materials and their properties.

A further object of the invention is to provide a sound reproducer wherein the largest effective sound radiating area is obtained which the ring is composed.

with a given diaphragm frame size and 'a minimum size hinge ring coupling to obtaln the greatest degree of flexibility where so desired. I y v V A still further object of the invention is to provide a supporting ring adapted for accordion action which, in combination w1th the inherent resiliency of the ring, enables the proper flexing thereof without materially straining the fibres of the material of Another object of the invention is to provide a supporting ring which Wlll maintain the conical diaphra min its true round shape but which has su cient resiliency to allow the diaphragm to function normally without producing audible buzzes.

Another object of the invention is to provide a supporting ring which, due to lts 1nherent uniformity, will hold the diaphragm in a uniform position and allow it to move in and out in a parallel plane in the air gap,

air gap possibly 'companying drawing in thereby eliminating the possibility ofseesaw I action, which naturally would result in buzzes due to the voice coil rubbing in the p at both extreme ends ofits vibratory motion particularly on the lower frequencies at high amplitudes.

. Other objects and characteristics of the invention will be clearly apparent from the following detailed description and the acwhich Fig. 1 illustrates the preferred form of the supporting ring in section; and Figs. 2 and 3 are similar sectional views showing the modified forms of the ring.

As illustrated in Fig. 1 of the drawing, the ring is provided with suitable corrugations, which general construction is, of course, common and well known in the sound reproducer art. I prefer, however, to construct the ring as clearly illustrated in the preferred embodiment of Fig. 1, wherein the flat annular portion 1 serves to firmly attach the ring to the diaphragm housing. Portion 2 is the corrugated .part of the ring and conical portion 3 serves to attach the diaphragm to the ring.

The ring maybe attached to the. diaphragm venience referred to as a double corrugation.. In Fig. 2, there is illustrated a form of ring in which a single corrugationis used,

while in Fig. 3, three corrugations are provided. For convenience, theseforms may be referred to as single'and triple corrugations respectively. I prefer the form of Fig. 1 because it appears to be the most practical in most instances, although the form of Fig.

2 may be used where extremely high rigidity and if the maximum depth er as is commonly of the type contemplated may is desired and the form of Fig. 3, may be used where extremely high flexibility is desired.

In accordance with the invention, the supporting ring which may take any of the designs illustrated or any other suitable design, is formed of rubberized paper, preferably alpha pulp fibre paper impregnated with rubber. This is advantageously accomplished by employing latex and precipitating the rubber particles upon the fibres during the manufacture of the paper or by the precipitation of the rubber particles on a sheet of paper passed through latex. The precipitation of the rubber particles upon the latex in either case is accomplished according to well known methods. Although the invention contemplates broadly the use of rubberized paper, the preferred materials have been found thus far to give the best results. The rubberized paper, however, may be formed by passing a sheet of paper through rubber dissolved in a suitable solvent (a rubber cement) or by treating the paper sheet with a water dispersion of rubber. The percentage of rubber to paper fibres in the rubberized paper product may vary widely, depending upon the exact properties desired in the sup porting ring. For example, if the paper is made from paper stock impregnated with precipitated latex during the manufacture of the paper, the product may contain 20% of rubber. In the method where the finished paper is impregnated with the latex solution and the rubber particles precipitated therefrom, a product containing up to rubber may be used. In the case of the impregnation of the paper with rubber cements and the like 15% of rubber in the product has been found to give satisfactory results. In the preferred method, the latex is added to thebeater after the paper fibres have been subjected to the beating operation. The rubber particles in the latex are precipitated upon the fibres according to the usual practices and the paper is thereafter formed on a paper machine or in any other suitable manemployed in the paper industry. When properly processed and treated, the rubber impregnated paper contemplated herein will be found to be especial- 1y strong and resilient, which characteristics are absolutely essential not only to the suc- 'oessful making of the ring in accordance with the method set forth hereinafter, but also to successful functioning of the ring when incor orated in a sound reproducer. It will be un erstood, of course, that rubberized paper have proper anti-oxidents or age-rights incorporated at the time of impregnating, in order that maximum life characteristics may be ob tained.

, Byproperly proportioning the thickness of t estock used and varying the physical out to its finished dimensions,

properties of the stock accordingly, almost any desired results as regards frequency response, flexibility, rigidity, etc. can be obtained in the finished ring without varying the dimensions of the ri By varying the physical properties of t e stock, I mean varying the raw components used therein. Thus, the characteristics of the completed ring will depend u'ponthe particular pulp utilized, the treatment of the pulp, the density of the sheets, the type of sizing, the absorbency of the finished stock, etc. The type of rubber used, the concentration of the impregnating solution, the method of impregnating, and other variable factors relating to the impregnating material and method will also determine the characteristics of the ring. Likewise, the process to which the finished stock is subjected will affect the characteristics. factors in relation to each other, the ring may be given any desired frequency response characteristic resulting from variations in its mechanical structure.

The mechanical structure and design of the supporting ring having been described, the process of making the same will now be set forth. This process involves the ordinary embossing process which is used generally in imparting desired shapes to paper sheet material, I have found, however, that to successfully emboss a ring of the type used herein into a permanent shape, the following procedure is practically necessary. A pair of dies are first formed in the following mannerz-A plate of hard metal, which ma be about one-halfinch in thickness, is machined to the sha e which it is desired to im art to the ring. rom this late,a second so t late is formed by providing a dam aroun the edge of the hard plate and or mold ing the soft plate from so meta such as lead-antimony of various percentage or Babbitt metal. The hard and soft plates are then placed in a hydraulic or similar press of sufficient tonnage to press the soft plate firmly against the hard plate and thus impart to the soft plate the exact contour of the hard plate. We now have the necessary dies with which to carr out the embossing process.

The most esirable type of press for embossing the ring of the resent invention is a Sheridan cam type embossing press either of the steam or electrically heated ty e. Such press should, of course, be of suitable tonnage, the tonna e depending upon the size and number of dies to be mounted at one time in the press. Other types of presses, such, for example, as quick-acting heated hydraulic presses may be used. Heating is required to soften the rubber and fibres to enable the proper embossin by allowing the stock to give or stretch. gVhen it is possible to emboss a ring that is alread cut or died have found urin or died out singly or in groups.

that the best results may be obtained by embossing the ring from a solid piece of stock with a uniform pressure across the die.

The heat of the press should be maintained as low as is possible to obtain a smooth even embossing and to keep the usual characteristics of the paper. In the case of latex impregnated paper, a temperature of from 140 to 160 sure applied should be suflicient to squeeze the stock down permanently from to 50% of its original thickness. It is necessary that the pressure be applied uniformly across the dies as a finished uniform thickness must be had if the completed ring is to maintain its shape and not warp or buckle. I have found that an initial thickness of .010 to .040 of an inch giving a finished ring of .005 to .020 of an inch in the thickess is very satisfactory, although these values are not to be taken as limiting the thickness of the ring to the range specified.

After a plurality of rings have been embossed as described above, they may be out A very satto punch out a single isfactory method 1s hole in each of the embossed pieces by means of a suitable die preferably at the time of the embossing. The embossed pieces may then be nested on a suitable pin. A number of embossed pieces can be cut at one time, depending upon the thickness of the material. In some cases, it may be possible and practical to emboss and cut a number of concentric rings of different size from the same piece of material.

While I 'am fully aware that cone diaphragms of sound reproducers have heretofore been formed with corrugated edges, such prior art devices have been impractical from the standpoint of manufacture thereof. The improved ring of the present invention readily lends itself to a simple and practical process of manufacture and at the same time has the highly desirable characteristics pointed out above. It is to be understood, of course, that the invention is not to be limited to the s ecific disclosure set forth herein which is or the purpose of illustration only. Only such limitations as are imposed in the appended claims are to be placed upon the invention.

I claim 1. A corrugated supporting ring for sound reproducing diaphragms composed of rubberized paper.

2. A corrugated supporting ring for sound reproducing diaphragms composed of rubber-impregnated paper.

3. A corrugated supporting ring for sound reproducing diaphragms composed of alpha pulp paper impregnated with precipitated latex.

4. A method of making a corrugated supporting ring for a sound reproducing dia- F. is desirable. The presaround the edge of hragm, which comprises embossing a ring ormed of rubberized paper.

5. A method of making a corrugated supporting ring for a sound reproducing diaphragm, which comprises treating paper with rubber in desired proportions to form stock, and embossing the stock to form the 6. A method of'making a corrugated supporting ring for a sound reproducing diaphragm, which comprises treating paper with rubber in desired proportions to form stock, forming a hard die member to the desired shape of the ring, forming a second die member from relatively soft material by pressing it against the hard member, and embossing the ring in said die members.

7. A method of making a corrugated supporting ring for a sound reproducing diaphragm, which comprises treating paper with rubber in desired proportions to form stock, forming a hard die member to the desired shape of the ring, providing a dam said member, molding relativelysoft material on said hard member to form a second die member, and embossing the ring in said die members.

SPENCER W. MoKELLIP. 

